I never used to get spam through GMail's filters, but in the last six-ish months I now get a couple every day. They're almost always the same format, too - frequently just a link, and often coming from an outlook.com email address.
So a possible hypothesis is that spammers got good at evading GMail's filter, so in tweaking it to catch these new spam techniques they could be causing more false positives.
I'm still surprised by how often people (not necessarily you!) forget about misaligned purposes: your purpose for using Gmail is to have a good email service; Google's purpose for running Gmail is to make money, _not_ necessarily by providing a good email service.
When purposes misalign like that, you get users bewildered about why such a competent company would be “incapable” of providing a less crappy service.
Compare with Thunderbird: they make money to pay the bills but no-one's getting rich. Their only way of getting money is by building a good email client — by building features that companies will pay them to build; or by making a general-purpose email client good enough that users will donate.
(I know Thunderbird is not directly equivalent because it's just a client, not an email server, but the email client part is comparable.)
I feel pretty bad for the ads team honestly. Like, their job is to basically just ruin products. Literally no one likes anything they do, ever. Their justification for everything is always just "You have to let us do this because $$$" and no one respects that, even though everyone knows that it's how the world works.
Practically speaking, most big (tech) companies probably have split teams for UI/Product and Ads. So there’s most likely a team of product managers and engineers at G who’s entire job is to make Gmail better - regardless of the ad team in the next building over. So those people literally don’t care about making G money per se, as long as they’re not introducing bugs into the ad showing logic or making it worse (see first point).
One of the rare areas where barrier to innovation isn't market access but actually product quality. That being said I wouldn't pay a lot for this as a standalone service, though I would definitely pay for a standalone email client at this point.
> Surely they see it.
(Question not directed at you specifically.)
I can't tell if this is just some sort of temporary spam filter tweaking error and oversight or an emergent property of a content-based filtering system that they won't revert.